Access: Take U.S. 36 north from Boulder to Lyons. Turn left onto South St. Vrain Canyon Road (Colo. 7) and continue to the Wild Basin turnoff, about 2 miles northwest of Allenspark. Turn west onto a road that dead-ends in 2.3 miles at the parking lot. The lot fills quickly, so plan to arrive early. In winter, the road makes an easy ski trail.

If you see a pink glint on the forest floor, look closer.

Dark, damp dells in the conifer forest may be lit up by magenta fairyslipper orchids that grow abundantly along the trail to Calypso Cascade. Calypso bulbosa, the scientific name for these small orchids with a lower petal shaped like a shoe and sepals like fairy wings, inspired the name of this cascade in Rocky Mountain National Park.

Usually fairyslippers bloom in June, but the record-breaking warmth this year may have put their schedules out of kilter. Even if you miss the fairyslippers, coralroot orchids should still be blooming. And, if you look very carefully beyond Ouzel Falls, you might find a rare brownie lady's slipper.

Ouzel Falls is named for the ouzels that often nest behind waterfalls. Nowadays the "correct" name for these dark-grayish birds that bob up and down and walk under water is American dipper. But we prefer the odd, older name derived from an Old English word, osle, meaning "black bird." Dippers belong to a family all their own and are not related to blackbirds.

Calypso Cascade is named for the fairyslipper orchids (Calypso bulbosa) that bloom abundantly along the trail in spring.
(Glenn Cushman)

This trail is one of our favorite places to see waterfalls. For most of its length, it follows North St. Vrain Creek (so wild it looks like one continuous waterfall) through shady coniferous forests mixed with aspen. On the southeastern tip of Rocky Mountain National Park, this trail actually lies in Boulder County. Park trails are well-maintained, providing signs with mileage at every junction and bridges across every creek.

Start at the south end of the Wild Basin Ranger Station parking lot. Be sure to stop at upper and lower Copeland Falls in 0.3 miles. A side trail makes a short detour to the falls, whetting (or wetting) your appetite for the even wilder falls to come. Just beyond Copeland Falls, a rock garden on the right is filled with wildflowers in spring and summer.

Ouzel Falls is named for the ouzels or American dippers that often nest behind it.
(Glenn Cushman)

Return to the main trail and climb 1.8 miles to Calypso Cascade. Botanist William Cooper named these falls and many other Wild Basin features when he mapped the area in 1911. His map sold for only 15 cents.

After viewing Calypso Cascade, take the Ouzel Lake Trail to the right. A trail to Finch and Pear Lakes veers to the left. In 1978, the Allenspark wildfire swept these ridges and took a month to contain. Snags of the incinerated forest still stand, but aspen, pine and extensive blueberry patches have largely revegetated the area. The fire did open up good views of Longs Peak, Mount Meeker and Copeland Mountain.

At 2.7 miles, Ouzel Falls thunders on your left. You can see it from the bridge, but it's worth taking the muddy side trail a short distance for full frontal views of this 40-foot fall. In addition to ouzels, look for the rare black swifts that nest behind the falls and listen for hermit thrushes and ruby-crowned kinglets.

There's lots more to see if you want to venture farther. From the bridge, the trail skirts a cliff and climbs to another junction, with the right fork heading to Thunder Lake and Boulder-Grand Pass, and the left fork continuing on to Ouzel Lake with another branch to Bluebird Lake.

Ruth Carol and Glenn Cushman are the authors of "Boulder Hiking Trails," published by Pruett Publishing Co., pruettpublishing.com.